Potassium Channel-Related Relaxation by Levosimendan in the Human Internal Mammary Artery Oguzhan Yildiz, MD, PhD, Melik Seyrek, MD, Vedat Yildirim, MD, Ufuk Demirkilic, MD, Cahit Nacitarhan, MD, PhD The Annals of Thoracic Surgery Volume 81, Issue 5, Pages 1715-1719 (May 2006) DOI: 10.1016/j.athoracsur.2005.12.057 Copyright © 2006 The Society of Thoracic Surgeons Terms and Conditions
Fig 1 Original tracing of phenylephrine (PE; 1 μmol/L) -precontracted human internal mammary artery ring showing relaxation to levosimendan (10 nmol/L to 3 μmol/L). The concentration was changed every 5 minutes after a plateau was reached. The Annals of Thoracic Surgery 2006 81, 1715-1719DOI: (10.1016/j.athoracsur.2005.12.057) Copyright © 2006 The Society of Thoracic Surgeons Terms and Conditions
Fig 2 Original tracing of phenylephrine (PE; 1 μmol/L)-precontracted human internal mammary artery ring showing no relaxation to acetylcholine (ACh; 10 μmol/L), which was used to test the success of endothelial denudation. The Annals of Thoracic Surgery 2006 81, 1715-1719DOI: (10.1016/j.athoracsur.2005.12.057) Copyright © 2006 The Society of Thoracic Surgeons Terms and Conditions
Fig 3 Cumulative relaxation to levosimendan in human internal mammary artery rings precontracted with phenylephrine (PE; 1 μmol/L) in the presence of (A) nitric oxide synthase inhibitor Nω-nitro-l-arginine methyl ester (l-NAME; 100 μmol/L; n = 6) and (B) cyclooxygenase inhibitor indomethacin (10 μmol/L; n = 6). Data are expressed as percentage of phenylephrine-induced maximum contraction. Vertical lines represent standard error of the mean. The Annals of Thoracic Surgery 2006 81, 1715-1719DOI: (10.1016/j.athoracsur.2005.12.057) Copyright © 2006 The Society of Thoracic Surgeons Terms and Conditions
Fig 4 Cumulative relaxation to levosimendan in human internal mammary artery rings precontracted with phenylephrine (PE; 1 μmol/L) in the presence of (A) 4-aminopyridine, a voltage-sensitive potassium-channel inhibitor (n = 8); (B) glibenclamide, an adenosine triphosphate–sensitive potassium-channel inhibitor (n = 10); and (C) tetraethylammonium chloride, a large-conductance calcium-activated potassium-channel inhibitor (n = 9). Data are expressed as percentage of phenylephrine-induced maximum contraction. Vertical lines represent standard error of the mean. *p < 0.05 and **p < 0.01 versus levosimendan control by paired Student’s t test. The Annals of Thoracic Surgery 2006 81, 1715-1719DOI: (10.1016/j.athoracsur.2005.12.057) Copyright © 2006 The Society of Thoracic Surgeons Terms and Conditions